Regulation of HTLV-I oncoprotein Tax by PDLIM2

Human T-cell leukemia virus type I (HTLV-I) is the etiological agent of adult T-cell leukemia (ATL). Its encoded oncoprotein Tax plays the key roles in HTLV-I-mediated cell transformation and pathogenesis. Although the mechanisms by which the HTLV-I Tax deregulates cellular signaling for oncogenesis have been extensively studied, how Tax itself is regulated remains largely unknown. Here we showed that PDZ-LIM domain-containing protein 2 (PDLIM2, SLIM or Mystique) negatively regulated Tax by promoting poly-ubiquitination and proteasomal degradation of Tax, so that to suppress Tax-mediated signaling activation, cell transformation and oncogenesis both in vitro and in animal. To further define the molecular determinant responsible for PDLIM2 mediated Tax suppression, we characterized that a putative á-helix motif of PDLIM2 at amino acids 236-254 was crucial for the interaction between PDLIM2 and Tax. PDLIM2 with selective disruption of this short helix lost the tumor suppression function and failed in altering Tax subcellular distribution as well as promoting Tax proteasomal degradation. Additionally, the expression of PDLIM2 was down-regulated in HTLV-I-transformed T cells and primary ATL samples, and the re-introduction of PDLIM2 reversed the tumorigenicity of the malignant cells. The evidence indicated that the counterbalance between HTLV-I Tax and PDLIM2 might determine the outcome of HTLV-I infection. Meanwhile, in those HTLV-I-transformed T cells, we found that DNA methyltransferases (DNMT) 1 and 3b but not 3a were over-expressed, suggesting the involvement of DNA methylation in PDLIM2 repression. Consistently, the hypomethylating agent 5-aza-2'-deoxycytidine (5-aza-dC) restored PDLIM2 expression and induced death of these malignant cells. Our studies provided important insights into the function of PDLIM2 in HTLV-I leukemogenicity, long latency and cancer heath disparities. Given the efficient antitumor activity with no obvious toxicity of 5-aza-dC, our studies also suggest potential therapeutic approaches for ATL, a disease with poor treatments

Study of “Catalytic Functions” of the “Friend” Roles of The Analects in Business Dealings

In international business dealings, we inevitably encounter problems arising from cultural obstacles, which in business dealings influence us greatly. However, the influence of cultural barriers can be decreased by the role of friends in business dealings. Also, the discussion of the “friend” roles of The Analects gives us theoretical basis for helping us to overcome cultural barriers. Previous research has showed that nowadays business dealings are affected by cultural obstacles, but it is found that the “friend” roles of The Analects can help us, to some extent, to remove the obstacles in business dealings. This paper cited many examples of the “friend” roles of The Analects, and their excellent characters are illustrated. These characters help us to promote the common cause, strengthen business relations, extend the partnership, and enjoy the cooperation in business dealings. Therefore, according to the “friend” roles of The Analects, we can stimulate “catalytic functions” in business dealings

Achieving high-quality silver sintered joint for highly-reliable schottky barrier diodes via pressureless method

The fabrication of silver joints was done using the pressureless sintering technology to suit the demand of high-reliability schottky barrier diodes (SBD). Porosity of 10.6% and shear strength of 39.6 MPa were reached under the optimized parameters of 290°C sintering temperature and 40 min residence time. The sintered joint demonstrated good mechanical/thermal/electrical performance in the ultimate reliability assessment testing, including the temperature cycling test, second sintering test, steady-state lifetime test, and intermittent lifetime test. This study demonstrated the viability of pressureless sintering of silver joints with good high-temperature reliability, which has significant application potential for aeronautical high-reliability power electronics

Self-regulating electrical rhythms with liquid crystal oligomer networks in hybrid circuitry

Self-regulation is an essential aspect in the practicality of electronic systems, ranging from household heaters to robots for industrial manufacturing. In such devices, self-regulation is conventionally achieved through separate sensors working in tandem with control modules. In this paper, we harness the reversible actuating properties of liquid crystal oligomer network (LCON) polymers to design a self-regulated oscillator. A dynamic equilibrium is achieved by applying a thermally-responsive and electrically-functionalized LCON film as a dual-action component, namely as a combined electrical switch and composite actuating sensor, within a circuit. This hybrid circuit configuration, consisting of both inorganic and organic material, generates a self-regulated feedback loop which cycles regularly and indefinitely. The feedback loop cycle frequency is tunable between approximately 0.08 and 0.87 Hz by altering multiple factors, such as supplied power or LCON chemistry. Our research aims to drive the material-to-device transition of stimuli-responsive LCONs, striving towards applications in electronic soft robotics.</p

Robotic pick-and-place operations in multifunctional liquid crystal elastomers

Pick-and-place operations for transporting objects precisely to a target position are a prominent function of (soft-) robotic systems. Therefore, there is great interest in industry to improve the characteristic gripping, holding, and releasing methods involved in pick-and-place operations. Within living organisms such as octopi, nature demonstrates that multiple types of conjointly working actuators are required for flexible pick-and-place operations. Herein, a multifunctional soft robotic arm is developed, capable of transporting an object within 3D space. The soft robotic arm consists of two structural actuators (rotating base and lifting unit) and a suction cup-based gripper. The structural actuator acts as both the load bearing and actuating components of the robotic system. Yet, the gripper is the crucial innovation within the robotic arm. A cephalopod-limb-inspired gripper functioning through the reversible flat-to-conical deformation of azimuthally aligned liquid crystal elastomer (LCE) films is proposed. The pressure-generating actuation mechanism of the gripper means that no external device is needed to operate the gripping function. Akin to natural systems, the in-tandem operation of the actuators in the soft robotic arm allows for multifactored tasks. Yet, the design achieves this through the use of a single material, which is not innate in natural archetypes

High temperature creep‐mediated functionality in polycrystalline barium titanate

Dislocations in oxides can be described as charged line defects and means for one-dimensional doping, which can tune electrical and thermal properties. Furthermore, theoretically it was shown that dislocations can pin ferroelectric domain walls. Broader application of this concept hinges on the development of a methodology to avail this approach to polycrystalline ceramics. To this end, we use different creep mechanisms as a method to introduce multidimensional defects and quantify structural changes. A deformation map for fine-grained barium titanate is provided and the influences of the defects and creep regimes are correlated in this first study to modifications of electrical conductivity, dielectric, ferroelectric, and piezoelectric properties. A plastic deformation of 1.29% resulted in an increase in the Curie temperature by 5°C and a decrease in electromechanical strain by 30%, pointing toward electromechanical hardening by dislocations

Structure, Phase Transition Behaviors and Electrical Properties of Nd Substituted Aurivillius Polycrystallines Na_0.5Nd_<i>x</i>Bi_{2.5–<i>x</i>}Nb₂O₉ (<i>x</i> = 0.1, 0.2, 0.3, and 0.5)

New high temperature Aurivillius piezoelectrics Na_0.5Nd_<i>x</i>Bi_{2.5–<i>x</i>}Nb₂O₉ (NDBN<i>x</i>, <i>x</i> = 0.1, 0.2, 0.3, and 0.5) with Nd substitution for Bi at the A site were synthesized using a solid state reaction process. Crystal structures of NDBN0.2 and NDBN0.5 were refined with the Rietveld method with powder X-ray diffraction, and they crystallized in the orthorhombic space group <i>A</i>2₁<i>am</i> [<i>a</i> = 5.48558(8) Å, <i>b</i> = 5.46326(9) Å, <i>c</i> = 24.8940(4) Å, and <i>Z</i> = 4 for NDBN0.2 and <i>a</i> = 5.46872(5) Å, <i>b</i> = 5.46730(5) Å, <i>c</i> = 24.80723(25) Å, and <i>Z</i> = 4 for NDBN0.5], at room temperature. The refinement results and Raman spectroscopy of NDBN<i>x</i> verified that Nd occupied both the A site in the perovskite layers and the cation site in the (Bi₂O₂)²⁺ layers. The Nd substitution induced an enhancement in cation disordering between the A site and the (Bi₂O₂)²⁺ layer and an increase in the degree of the relaxation behavior for NDBN<i>x</i>. The ferroelectric to paraelectric phase transition temperature (<i>T</i>_c) of NDBN<i>x</i> ranged from 735 to 764 °C. Furthermore, the isovalent substitution of Nd for Bi had a great influence on microstructure (grain size and shape), defect concentration (mainly oxygen vacancies), preferred grain orientation (texture), and distortion of the octahedron. The coaction between these effects determined the structure characteristics, phase transition behaviors, and electrical properties of NDBN<i>x</i>